Added SegmentFruit

examples/custom_collector.rs

@@ -70,6 +70,8 @@ impl Collector for StatsCollector {
     // Our standard deviation will be a float.
     type Fruit = Option<Stats>;
 
+    type SegmentFruit = Self::Fruit;
+
     type Child = StatsSegmentCollector;
 
     fn for_segment(

src/collector/count_collector.rs

@@ -58,6 +58,7 @@ pub struct Count;
 
 impl Collector for Count {
     type Fruit = usize;
+    type SegmentFruit = usize;
 
     type Child = SegmentCountCollector;
 

src/collector/facet_collector.rs

@@ -258,6 +258,8 @@ impl FacetCollector {
 impl Collector for FacetCollector {
     type Fruit = FacetCounts;
 
+    type SegmentFruit = FacetCounts;
+
     type Child = FacetSegmentCollector;
 
     fn for_segment(

src/collector/mod.rs

@@ -136,8 +136,10 @@ pub trait Collector: Sync {
     /// e.g. `usize` for the `Count` collector.
     type Fruit: Fruit;
 
+    type SegmentFruit: Fruit;
+
     /// Type of the `SegmentCollector` associated to this collector.
-    type Child: SegmentCollector<Fruit = Self::Fruit>;
+    type Child: SegmentCollector<Fruit = Self::SegmentFruit>;
 
     /// `set_segment` is called before beginning to enumerate
     /// on this segment.
@@ -152,7 +154,7 @@ pub trait Collector: Sync {
 
     /// Combines the fruit associated to the collection of each segments
     /// into one fruit.
-    fn merge_fruits(&self, segment_fruits: Vec<Self::Fruit>) -> Result<Self::Fruit>;
+    fn merge_fruits(&self, segment_fruits: Vec<Self::SegmentFruit>) -> Result<Self::Fruit>;
 }
 
 /// The `SegmentCollector` is the trait in charge of defining the
@@ -181,6 +183,9 @@ where
     Right: Collector,
 {
     type Fruit = (Left::Fruit, Right::Fruit);
+
+    type SegmentFruit = (Left::SegmentFruit, Right::SegmentFruit);
+
     type Child = (Left::Child, Right::Child);
 
     fn for_segment(&self, segment_local_id: u32, segment: &SegmentReader) -> Result<Self::Child> {
@@ -195,7 +200,7 @@ where
 
     fn merge_fruits(
         &self,
-        children: Vec<(Left::Fruit, Right::Fruit)>,
+        children: Vec<(Left::SegmentFruit, Right::SegmentFruit)>,
     ) -> Result<(Left::Fruit, Right::Fruit)> {
         let mut left_fruits = vec![];
         let mut right_fruits = vec![];
@@ -236,6 +241,7 @@ where
     Three: Collector,
 {
     type Fruit = (One::Fruit, Two::Fruit, Three::Fruit);
+    type SegmentFruit = (One::SegmentFruit, Two::SegmentFruit, Three::SegmentFruit);
     type Child = (One::Child, Two::Child, Three::Child);
 
     fn for_segment(&self, segment_local_id: u32, segment: &SegmentReader) -> Result<Self::Child> {
@@ -249,7 +255,7 @@ where
         self.0.requires_scoring() || self.1.requires_scoring() || self.2.requires_scoring()
     }
 
-    fn merge_fruits(&self, children: Vec<Self::Fruit>) -> Result<Self::Fruit> {
+    fn merge_fruits(&self, children: Vec<Self::SegmentFruit>) -> Result<Self::Fruit> {
         let mut one_fruits = vec![];
         let mut two_fruits = vec![];
         let mut three_fruits = vec![];
@@ -295,6 +301,7 @@ where
     Four: Collector,
 {
     type Fruit = (One::Fruit, Two::Fruit, Three::Fruit, Four::Fruit);
+    type SegmentFruit = (One::SegmentFruit, Two::SegmentFruit, Three::SegmentFruit, Four::SegmentFruit);
     type Child = (One::Child, Two::Child, Three::Child, Four::Child);
 
     fn for_segment(&self, segment_local_id: u32, segment: &SegmentReader) -> Result<Self::Child> {
@@ -312,7 +319,7 @@ where
             || self.3.requires_scoring()
     }
 
-    fn merge_fruits(&self, children: Vec<Self::Fruit>) -> Result<Self::Fruit> {
+    fn merge_fruits(&self, children: Vec<Self::SegmentFruit>) -> Result<Self::Fruit> {
         let mut one_fruits = vec![];
         let mut two_fruits = vec![];
         let mut three_fruits = vec![];

src/collector/multi_collector.rs

@@ -18,6 +18,7 @@ pub struct CollectorWrapper<TCollector: Collector>(TCollector);
 
 impl<TCollector: Collector> Collector for CollectorWrapper<TCollector> {
     type Fruit = Box<Fruit>;
+    type SegmentFruit = Box<Fruit>;
     type Child = Box<BoxableSegmentCollector>;
 
     fn for_segment(
@@ -34,10 +35,10 @@ impl<TCollector: Collector> Collector for CollectorWrapper<TCollector> {
     }
 
     fn merge_fruits(&self, children: Vec<<Self as Collector>::Fruit>) -> Result<Box<Fruit>> {
-        let typed_fruit: Vec<TCollector::Fruit> = children
+        let typed_fruit: Vec<TCollector::SegmentFruit> = children
             .into_iter()
             .map(|untyped_fruit| {
-                Downcast::<TCollector::Fruit>::downcast(untyped_fruit)
+                Downcast::<TCollector::SegmentFruit>::downcast(untyped_fruit)
                     .map(|boxed_but_typed| *boxed_but_typed)
                     .map_err(|e| {
                         let err_msg = format!("Failed to cast child collector fruit. {:?}", e);
@@ -152,7 +153,7 @@ impl<TFruit: Fruit> FruitHandle<TFruit> {
 #[derive(Default)]
 pub struct MultiCollector<'a> {
     collector_wrappers:
-        Vec<Box<Collector<Child = Box<BoxableSegmentCollector>, Fruit = Box<Fruit>> + 'a>>,
+        Vec<Box<Collector<Child = Box<BoxableSegmentCollector>, Fruit = Box<Fruit>, SegmentFruit = Box<Fruit>> + 'a>>,
 }
 
 impl<'a> MultiCollector<'a> {
@@ -177,7 +178,9 @@ impl<'a> MultiCollector<'a> {
 }
 
 impl<'a> Collector for MultiCollector<'a> {
+
     type Fruit = MultiFruit;
+    type SegmentFruit = MultiFruit;
     type Child = MultiCollectorChild;
 
     fn for_segment(

src/collector/tests.rs

@@ -40,6 +40,7 @@ impl TestFruit {
 
 impl Collector for TestCollector {
     type Fruit = TestFruit;
+    type SegmentFruit = Self::Fruit;
     type Child = TestSegmentCollector;
 
     fn for_segment(
@@ -109,6 +110,8 @@ impl FastFieldTestCollector {
 
 impl Collector for FastFieldTestCollector {
     type Fruit = Vec<u64>;
+    type SegmentFruit = Self::Fruit;
+
     type Child = FastFieldSegmentCollector;
 
     fn for_segment(
@@ -165,6 +168,7 @@ impl BytesFastFieldTestCollector {
 
 impl Collector for BytesFastFieldTestCollector {
     type Fruit = Vec<u8>;
+    type SegmentFruit = Self::Fruit;
     type Child = BytesFastFieldSegmentCollector;
 
     fn for_segment(

src/collector/top_field_collector.rs

@@ -88,6 +88,7 @@ impl<T: FastValue + PartialOrd + Clone> TopDocsByField<T> {
 
 impl<T: FastValue + PartialOrd + Send + Sync + 'static> Collector for TopDocsByField<T> {
     type Fruit = Vec<(T, DocAddress)>;
+    type SegmentFruit = Vec<(T, DocAddress)>;
 
     type Child = TopFieldSegmentCollector<T>;
 

src/collector/top_score_collector.rs

@@ -89,6 +89,7 @@ impl TopDocs {
 
 impl Collector for TopDocs {
     type Fruit = Vec<(Score, DocAddress)>;
+    type SegmentFruit = Vec<(Score, DocAddress)>;
 
     type Child = TopScoreSegmentCollector;
 

src/core/searcher.rs

@@ -23,7 +23,7 @@ fn collect_segment<C: Collector>(
     weight: &Weight,
     segment_ord: u32,
     segment_reader: &SegmentReader,
-) -> Result<C::Fruit> {
+) -> Result<C::SegmentFruit> {
     let mut scorer = weight.scorer(segment_reader)?;
     let mut segment_collector = collector.for_segment(segment_ord as u32, segment_reader)?;
     if let Some(delete_bitset) = segment_reader.delete_bitset() {